Wondrous prehistory, thanks to Robert Krulwich:
This is the story of two continents doing battle, North America versus South America. It is also a biological mystery.
For a very long time, North America and South America were separate land masses. The Pacific Ocean slipped between them, flowing into the Caribbean. The Isthmus of Panama was there, but it was underwater. The two continents didn’t touch.
As a result animals on both continents, especially mammals, evolved independently. They didn’t, couldn’t, interbreed. And yet, both North and South America had mountains, plains, long lazy rivers, deltas and supported similar forms of mammalian life. In fact, when biologists look back at the fossils, they found almost mirror like populations. Continue reading


















